Dyeing of cellulose derivatives



Patented Oct. 28, 1930 UNITED STATES PATENT, OFFICE GEORGE RIVAT,

SEY, CAMILLE DREYFU S, POBATION OF AMERICA, A

0F PATEBSON, ERNEST GADGENE, OF ENGLEWOOD GLHFS, NEW JER- OF NEW YORK,N. Y., ASSIGNORS TO CELANESE GOR- GORZPORATION OF DELAWARE DYEING OFGELLULOSE DERIVATIVES Io Drawing.

The object of this invention is to provide a process of fixing ironsalts on or in materials containing organic derivatives of cellulose.Another object of this invention is to provide a process for fixing ironsalts on or in materials containing organic esters of cellulose, moreparticularly cellulose acetate. Still another object of the invention isto provide a process for treating organic derivatives of cellulose sothat they may be dyed more easily and with more satis fabctory resultsthan has heretofore been possi le.

It is customary when it is desired to mordant silk, etc., with ironsalts, that'an iron salt solution of 1 to 5% strength he used. Thisprocess when applied to materials containing organic esters ofcellulose, results in no appreciable fixation of iron in the material.The applicants have now discovered that if material containing organicesters of cellulose is treated with a highly concentrated solution ofiron salts, appreciable amounts of the iron are easily fixed in or onthe cellulose derivative treated. The strength of the iron salt solutionshould be between 40 to by weight in order to obtain good results.

As an example of the operation of the process the following is given:

A fabric made from cellulose acetate was treated in a 50% bath of ferricchloride for one hour. The bath was first heated to 40 degreescentigrade which was gradually increased to degrees centigrade. Thematerial was then squeezed or whizzed to remove the excess of the ironsolution, after which it was washed in water for twenty minutes. Afterthis washing the material was again washed, this time in cold watercontaing 1 c. c. of ammonia per litre of water.

The fabric after the above treatment was orange colored but wasunchanged in other respects. It still retained its lustre and itssoftness. The iron was per anently fixed in the cellulose acetate and co(1 not be removed even when the material was treated with hydrochloricacid. The fabric treated as above when washed was found to contain1.8-2% of 113011.

The applicants have discovered that a fab- Application filed June 30,

materials containing 1926. Serial No. 119,742.

ric which has been subjected to the above treatment can be dyed with theso-called natural or vegetable dyes. When such fab- -rics are dyed withthis class of dyes unexpected results are obtained. The colors are veryfast and deep whereas similar fabrics when untreated do not this classof dyes.

Thus when a cellulose acetate fabric which Was first treated with ferricchloride, washed, etc., as set out above, was immersed in a regularlog-wood black bath in soap, say at a temperature of .C., for one hourit was found to have been dyed a beautiful black, much superior inappearance to that previously ob tainable with this dye.

Where a mixed fabric of cellulose acetate and silk, of cellulose acetateand wool or of dye at all well withcellulose acetate, silk and wool, wastreated since the mixed fabric does not have to be" passed thru two orthree different dye baths, as is the practice today. What has been saidabove with respect to the logwood dyeing of the organic derivatives ofcellulose is also true of other natural or vegetable dyes or dyeextracts such as, for example, young fustic, fustic, quercitron, Persianberries, weld extract, turmeric, sandalwood, cutch, etc. or any otherdyes or mi tures of dyes which are suitable for dyeing a materialmordanted with iron. The choices of dyes will depend upon the colorwhich it is desired to dye the material. In all cases after the dyeingthe goods must be washed as is customary in similar ordinary dyeingprocesses.

In the event it is desired to tint the black obtained by the logwooddyeing-either bluer or greener, this can be accomplished by adding theproper dyestuffs to the logwood bath. For the cellulose acetate fabrican SRA dyestulf (that is a water insoluble dyestuif having an affinityfor cellulose acetate material and. generally applied in the form of anlose,

. terials such aqueous dispersion obtained for instance with the aid ofa. dispersing agent) may be used whereas a basic dyestuif may beemployed to tint real silk if it is present and an acid dyestuff forW001. The above examples are mere- 1 illustrative and merely set out afew of the numerous possible methods of carrying out the applicantsinvention. Thus the ferric chlorlde can be replaced by any other solubleferric salt such as, for instance, ferric sulphate, ferric nitrate, etc.Also the cellulose acetate can be replaced by cellulose propionate,cellulose butyrate, ethyl celluetc. and, as stated above, logwood may bereplaced by, fustic or other dyes as stated above.

This process is applicablenot only to materials made wholly of organicderivatives of cellulose but can also be utilized to treat mixtures ofsuch derivatives and other maas, for example, mixtures of celluloseacetate and wool, cellulose acetate and silk, and cellulose acetate andwool and silk with very desirable results. The treatment of suchmixtures, however, is to be considered within the scope of thisinvention.

Having described our invention what we desire to claim by "LettersPatent is:

1. A process of treating organic derivatives of cellulose whichcomprises subjecting the same to the action of a concentrated solutionof a ferric salt.

2. A process of treating organic derivatives of cellulose whichcomprises subjecting the same to the action of a 40 to 55% solution offerric chloride. 1

3.' A process of treating organic esters of cellulose .which comprisessubjecting the same to the action of a concentrated solution of a ferricsalt.

4. A process of treating organic esters of cellulose which comprisessubjecting the same to the action of a 4:0 to 55% solution of ferricchloride.

5. A process of treating organic esters of cellulose which comprisessubjecting the same to the action of a 50% solution of ferric chloride.

6. A process of treating organic esters of cellulose which comprisessubjecting the same to the action of a concentrated sol ion of ferricchloride at temperatures above atmospheric and below C.

7. A process of treating organic esters of cellulose which comprisessubjecting the same to the action of a 50% solutionof ferric chloridefor approximately one hour at 40 to 60 C.

8. A process of treating organic esters of cellulose which comprisessubjecting the same' to the action of a 50% solution of ferric chloridefor approximately one hour at 40 to 60 C. removing the excess ironchlothen washing the material with which action warm water and finallywashing it with cold water containing ammonia.

9. A process of treating cellulose acetate which comprises subjectingthe same to the acltion of a concentrated solution of a ferric sa t.

10. A process'of treating cellulose acetate which comprises subjectingthe same to the action of a concentrated solution of ferric chloride.

11. A process of treating cellulose acetate comprises subjecting thesame to the of a 50% solution of ferric chloride. A process of treatingcellulose acetate comprises subjecting the same to the of a 50% solutionof ferric chloride. for approximately one hour at 40 to 60 C.

13. A process of treating cellulose acetate which comprises subjectingthe same to the action of a 50% solution of ferric chloride for.approximately one hour at 40 to 60 C. removin the'excess iron chloridesolution, then washing the cellulose acetate with water and finallywashing it with cold water containing ammonia.

14. A process of treating organic esters of cellulose which comprisessubjecting the same to the action of a concentrated solution of a ferricsalt, removing the excess ferric salt solution, then washing thematerial with warm water, again washing with cold water containingammonia, and then treating the thus Washed material with a dye extractand then finally washing the dyed material as action 12. which usual. I

15. A process of treating organic esters of cellulose which comprisessubjecting the same to the action of a 50% solution of ferric chlorideremoving the excess ferric chloride solution, then washing the materialwith water, again washing with cold water containing ammonia, and thentreating the thus washed material with a natural dye extract and thenfinally washing the dyed material as usual.

16. A process of treating cellulose acetate which comprises subjectinthe same to the action of a 50% solution of erric chloride forapproximately one hour at 40 to 60 0., removing the excess ferricchloride solution, then washing the acetate with warm water, againwashing, with cold Watef containing ammonia, then'treating the thuswashed material with a natural dye'extract and finally subjecting thedyed material to the usual washing operations.

7. A process of treating cellulose acetate washing wi subjecting thedyed material to the usual washing operations.

18. A process of treating cellulose acetate which comprises subjectingthe same to-the action of a 50% solution of ferric chloride forapproximately one hour at 40 to 60 C., re-

moving the excess ferric chloride solution, then washin the acetate withwater, again t h cold water containing ammonia, then treatin the thuswashed material with the regu ar logwood black bath in soap for one hourat approximately 70 C.

19. A process of treating a mixed fabric containing wool and celluloseacetate which comprises subjecting said fabric to the action of a 50%solution of ferric chloride for approximately 1 hour at 4.0 to 60 C.

20. A process of treating a mixed fabric of wool and cellulose acetatewhich comprises subjecting said fabric to the action of a 50% solutionof ferric chloride for approximately 1 hour at 40 to 60 (3., removingthe excess ferric chloride solution, then washing the fabric with water,again washing with cold water containing ammonia, then treating the thuswashed fabric with 10 wood extract and thereafter subjecting the yedfabric to the usual washing operations.

21. Cellulose acetate having 1.82% of iron fixed therein by treating thecellulose acetate with a 50% solution of ferric chloride.

22. Cellulose acetate havin 1.82% of iron fixed therein and dyed withogwood extract thereon.

23. A mixed fabric containing wool and cellulose acetate having 1.82%iron fixed therein.

In testimony whereof, they have hereunto subscribedtheir names.

GEORGE RIVAT. ERNEST CADGENE. I CAMILLE DREYFUS.

